An approximate model for the adhesive contact of rough viscoelastic surfaces

TL;DR

This paper introduces an analytical model for the adhesive contact of rough viscoelastic surfaces, accounting for viscoelastic effects like stress relaxation and creep, and demonstrates how viscoelasticity can restore adhesion despite surface roughness.

Contribution

It presents a simplified analytical model for viscoelastic rough surface adhesion, extending previous sphere contact models and integrating statistical surface roughness effects.

Findings

Moderate viscoelasticity significantly enhances adhesion on rough surfaces.

The model captures key viscoelastic phenomena such as stress relaxation and creep.

Adhesion can be quantitatively assessed using the proposed combined model.

Abstract

Surface roughness is known to easily suppress the adhesion of elastic surfaces. Here a simple model for the contact of \emph{viscoelastic} rough surfaces with significant levels of adhesion is presented. This approach is derived from our previous model [E. Barthel and G. Haiat {\em Langmuir}, 18 9362 2002] for the adhesive contact of viscoelastic spheres. For simplicity a simple loading/unloading history (infinitely fast loading and constant pull-out velocity) is assumed. The model provides approximate analytical expressions for the asperity response and exhibits the full viscoelastic adhesive contact phenomenology such as stress relaxation inside the contact zone and creep at the contact edges. Combining this model with a Greenwood-Williamson statistical modeling of rough surfaces, we propose a quantitative assessment of the adhesion to rough viscoelastic surfaces. We show that moderate viscoelasticity efficiently restores adhesion on rough surfaces over a wide dynamic range.